Safety-guard for power-presses.



APPLICATION FILED OCT-6. 1913- Patented M11213, 1915.

4 SHEETS-SHEET 1.

THE NORRIS PETERS 50.. PHOTO-LITHO.v WASHINGTON. Dv C.

J, WRIGHT.

SAFETY GUARD FOR POWER PRESSES.

APPLICATION FILED 001.6. 1913.

Patented Apr. 13, 1915.

4 SHEETS-SHEET 2.

THE NORRIS PETERS co., PHOTO-LITHCR WASHINGIQN. u c.

APPLICATION FILED 0CT.6. I913.

Patented Apr. 13, 1915.

4 SHEETS-SHEET 3.

THE NORRIS PETERS 60.. PHOTO-LITHQ. WASHINGTON D. C.

1'. WRIGHT.

SAFETY GUARD FOR POWER PRESSES.

APPLICATION FILED OCT. 6. 1913.

Patented Apr. 13, 1915.

4 SHEETS-SHEET 4.

ven im? JAMES WRIGHT, OF HAMILTON, ONTARIO, CANADA.

SAFETY-GUARD FOB POWEB-ERESSES. 1

Specification of Letters ratent.

"Patented Apr. t3, 11%115.

Application filed October 6, 1913. Serial No. 793,747.

To (ZZZ whom it may concern:

Be it known that 1, JAMES WRIGHT, a subject of the King of Great Britain, and a citizen of the Dominion of Canada, residing at 264. Cannon street east, in the city of Hamilton, in the county of Wentworth, Province of Ontario, Dominion of Canada, have invented certain new and useful improvements in Safety-Guards for Powerl resses, of which the following is a specification.

'1 his invention relates to safety guards for power presses and it has more particular reference to stamping press guards which are intended to prevent injury to the fingers or hands of the operator.

The main object of my present invention is to provide a safety guard which moves or always travels slightly in advance of and with the reciprocating tool and thereby positively insures the operator being warned of approaching danger.

it further object of my invention consists in arranging the movement of the protective element proper, to synchronize with the operation of the press in contra-distinction to devices heretofore usually construct ed "hich are brought into the protective posi by the movement of the foot lever or treadle prior to the release of the clutch.

it still further object of my invention is to provide a safety guard with means whereby the protective device is moved down in advance of the downward movement of the reciprocatory tool and prevents the said re' ciprocatory tool from being moved down by its operating mechanism when the guard or protective device encounters an obstructionfor example the fingers or hand of the operator-with the result said tool is effectively prevented from moving down if the hand. or fingers of the operator have not been removed before the protective device has been descended.

i v ith these and other objects in view, as will more fully hereinafter appear, my in vention consists in the novel features of construction, combination and arrangement of parts hereinafter fully described, illustrated by the accompanying sheets of drawings forming a part of this specification, and more specifically pointed out in the appended claims.

In the drawings, Figure 1 is a perspective view taken at the rear of a power press and showing the protective element descend- 1ng 1n advance of the plunger. Fig. 2, is a similar view but showing the position of the protective element and its appurtenant parts as and when said protective element encounters an obstruction. Fig. 8, is a side elevation of the press showing the position of the protective element when raised; the driving wheel being removed to illustrate the dog release. Fig. i, is a detail hereinafter specifically referred to. Fig. 5 is a vertical sectional view of the machine, and Fig. 6 is a detailed view of a latch hereinafter described.

Similar numerals of reference are employed to indicate corresponding parts in all the figures of the drawings.

This application exemplifies one convenient form of stamping press having my in vention applied thereto, and of which presses there are several kinds, all of which can have my protective device readily ap* plied thereto, small modifications only be ing required to adapt my said invention to the particular type of press.

The stamping pressa small bench pressfor working on sheet or other metal shown in the drawings consists essentially of a base plate 1, for fixture in any desired position by holding down bolts, and on said base the die 2, is firmly secured in any appropriate or well known way.

3, d, are vertical standards united at their upper ends by a cross piece or beam 5.

6, is the driving shaft on which the continuously-rotating driving wheel 7, is appropriately. mounted, said shaft being journaled in bearings 8, 9, transversely at the upper part of the press. 7

10, is the crank to which the head of the pitman 11, is pivotally connected, said pitman in turn being hingedly united at its lower end to the vertically movable crosshead 12, which is guided in guides 13, on the aforesaid vertical standards 3, ti; and 14:, is the plunger or male die, carried by said crosshead 12.

The clutch is preferably of the form described in my co-pending application Serial No. 776,722, and which briefly embodies an oscillatory coupling bar 15,-Fig. 3--a col lar 16, upon the driving shaft 7, a radially disposed arm 17, carried by said coupling bar 15, and projecting through said collar 16, and ratchet teeth 18, formed on said collar. These elements forming part of the subject matter of the above referred to application will therefore not be more fully described.

. For ,coupling the clutch, I hinge at the outer side of the standard 3, by means of a pivot pin 19, an oscillatable arm or lever 20, which in turn is provided at its free end 21, with a notched out part. 22, in which is rockably disposed a dog or tooth 23, under the action of a cushion spring 24. This arm 20, and dog 23, are controlled and operated by means of a connecting rod 25,'coupled to the trip lever 26, which is under the action of a spiral or other suitable spring 27, all in the well known way. It is to be here noted that mounting the dog 23, as set forth prevents a direct metal to metal contact with the nose of the arm 17, with the result that undue shocks and unnecessary wear and tear are obviated. I

28, is the protective element or guard proper, arranged mounted and operated according to my invention, as follows:-This protective element proper may be of any suitable pattern or contour in plan to suit the male die or plunger 14, of the press to whichthe device is to be attached. In the form shown it embodies a ring portion 28, surrounding the male die 14, and a rearwardly projecting arm or bar 29; and said arm or bar 29, is rearwardly or forwardly adjustable in an eye piece 30, at the lower end of a square section carrier bar 31. j

32, is a set screw for locking the arm 29, in adjusted position.

The carrierbar 31, is vertically adjustable between the spaced jaws 33,Fig. %of a rockable block 34, pivotally mounted at 35,

on a suitable pivot carried by the pressplunger, and said block 34, is normally retained vertical by a tension spring 36, connected thereto and to the plunger of the press. The carrier bar 31, is upwardly extended and reduced to circular section at 37, and is under the action of a compression spring 38, seated between the upper jaw 33, and the top end of the square section 31.

39, is a lock nut for fixing the bar 31, in adjusted position.

Threaded on the upper end of the part 37, is an extension 40, headed by lock nuts 41, said lock nuts serving as an adjustment to adapt the machine to act upon either light or heavy stock whereas the lock nut 39, serves to regulate the protective element for long or short punches. The extension 40, is rearwardly and forwardly rockable in a slotted bracket or supporting plate 42, and said plate carries a depending rod'43-adjustable by lock-nuts 44for the purpose hereafter explained. I

45, is an upstanding bar adjustably fixed in the rear end of the rockable block 34, by means of clamping screws 46, 47 and said bar is fitted at its upper end with an antifriction roller 48, which in turn is adapted shaped stop integral with an adjustable strip 50, as hereafter explained. The substantially V-shaped stop is disposed with its forward face vertical so that the protective device 28, when meeting with no obstruction may descend and ascend vertically while the anti-friction roller 48, rides easily up and down the vertical face of said stop 49. The strip 50, is adjustable longitudinally of an oscillatable bar 51, fulcrumed at 52, to a bracket 53, fixed to the inside of the standard 3. Said oscillatable bar 51, is fashioned with a V -shaped upper end 54, which serves as a latch for the end 55, of a lever 56, pivoted at 57, on the outer face of the standard 3, adjacent its upper end. This lever 56, is fashioned somewhat L-shaped and is provided with a nosed or pawl shaped end 58, which is adapted to coiiperate with the above referred to ratchet teeth 18, when the oscillatable bar 51, is released from the lever 56.

59, is a tension spring connected to the lever 56, and to the side of the standard 3, and said lever is provided with a series of spaced holes 60, for varying the tension of the spring 59. Or, two or more springs 59, may be employed as will be obvious.

A latch 61, indicated by dot-and-dash lines in Fig. 3 and in detail in Fig. 6, may be fitted'to the bracket 53, for preventing the accidental return of the lever 56, and the release of the pawl end 58, from the ratchet teeth 18, when the protective element meets an obstruction and the device operates to arrest the movement of the press.

62, is a stop-appropriately a square headed set-screw against which the lower end of the depending rod 43, contacts as the plunger of the press nears its highest position with the result that the protective element 28, is upwardly tilted as shown in Fig. 3, out of the way. Immediately the press is again tripped the protective element 28, automatically moves back to its normal position under the action of the spring 36.

The operation of my improved safety guard for power presses is briefly as follows :-lVhen the guard is tripped by depressing the lever 26, the plunger and punch 14, commence to descend carrying with them the protective element 28, said element 28. traveling in advance of the lower face of the punch 14. If no obstruction is encountered the punch 14, will operate on the stock and enter the die 2, from one-sixteenth to one-half inch. Simultaneously with the punch touching the stock the lock nuts 4-1, contact with the bracket 42, and hold the protective element 28, from further descent and retain the parts 31, 37, and 40, all vertimesses cal; or, in other words, without any rearward inclination, the further descent of the punch 14, carrying with it the bracket 34:, in opposition to the resistance of the spring 38. As the punch 14, rises on the return stroke the protective element 28, and parts 311, 37, and 40, are automatically returned to their normal position by the action of the spring 38. Assuming the protective element 528, encounters an obstruction such as the fingers or hand of the operator, it will be raised with the r sult that the parts 31, 37,

and d0, will be rearwardly deflected causing the roller 48, to immediately contact with the vertical face of the stop 4E9. linstantly this act-ion takes place the oscillatory bar 51, will be released from engagement with the lever 56, and forwardly projected as shown in Fig. Simultaneously with this operation the lever 56, will be snapped downwardly by the spring or springs 59, and the pawl. portion 58, locked in one of the teeth id, of the collar 16, which will result in the arrestation of the further descent of the punch l l, as it cannot contact with the obstruction owing to the fact that the protective element 28, is traveling in advance thereof. The contact of the protective elemen" 28, with the obstructionthe fingers or hand of the operator-gives an immediate warning of approaching danger and even if said obstruction is not instantly withdrawn-as the protective element can not further descendolie punch l-a-l, is absolutely arrested before it can come in contact therewith. Another important fcature of my device is, assuming the protective element to be deliberately held upward when the press is tripped, as the punch. 14:, descends the parts 31, S7, and 40, will be deflected rearwardly and the roller 48, caused to strike the inclined face of thestop 49, in suring the oscillatory bar 51, being rearwardly thrown with the consequent arrestation of the further descent of the punch 14,

by the parts 56, 58, and 18, as above set forth.

From the foregoing description and accompanying drawings it will be readily seen that by my invention 1 provide an extremely effective and reliable device for the purpose set forth, while in no way interfering with I the utility or etliciency of the press, all that is necessary being the tapping of a few holes and the insertion of screws or bolts to attach the entire safety device in position.

Ubviously my invention may be readily adapted to any type of stamping press or machine having a reciprocatory tool worked or operated by a clutch release mechanism,

all the parts are mad relatively adustable. Therefore, it wish it clearly understood that I do not confine myself to the specific arrangement and combination of parts illustrated and described, various alterations in their form and the arrangement of the details thereof being possible without in any way departing from the spirit and scope of the invention; and it is intended fully to include all such within the present application, which may be reasonably construed as falling within the ambit of the appended claims:

Having thus described my invention, what I claim as new and desire to secure by Let ters Patent, is

l. In a device of the character described, the combination with the press plunger, of a tiltable element pivoted thereon, a guard carrying element mounted to reciprocate in said tiltable element, spring means resisting such reciprocatory movement in one direction, a brake mechanism, means controllable by the tilting of said tiltable element from normal position for throwing said brake mechanism into action to arrest the movement of the plunger, and means for tilting said tiltable member from normal position when the press plunger reaches its upper limit of movement.

2. In a device of the character described, the combination with the press plunger, of a tilt-able element pivoted thereon, a guard carrying element mounted to reciprocate in said tiltable element, spring means resisting such reciprocatory movement in one direction, a brake mechanism, means controllable by the tilting of said tiltable element from normal position for throwing said brake mechanism into action to arrest the movement of the plunger, means for tilting said tiltable member from normal position when the press plunger reaches its upper limit of movement, and means for adjusting said last named means.

3. In a device of the character described, the combination with a reci nrocatory press plunger, of a tiltable element carried thereby, a guard carrying element carried by said rcciprocatory element and capable of movement with relation thereto, and means for limiting the movement of said guard carrying element, said tiltable element being capable of a limited additional movement in conjunction with the press plunger after the movement of the guard carrying element ceases.

4:. In a device of the character described, the combination with a reciprocatory press plunger, of a tiltablc elcmcntcarried thereby, a guard carrying element carried by said reciprocatory element and capable of move ment with relation thereto, means for limiting the movement of said guard carrying element, said tilting element being capable of a limited additional movement in conjunction with the press plunger after the movement of the guard carrying element ceases, and spring means disposed between said guard carrying element and said tiltable element and arranged to be placed under tension during such additional movement.

5. In a device of the character described, the combination with a reciprocatory press plunger, of a tiltable element carried thereby, a guard carrying element carried by said reciprocatory element and capable of movement with relation thereto, means for limiting the movement of said guard carrying element, said tilting element being capable of a limited additional movement in con junction with the press plunger after the movement of the guard carrying element ceases, spring means disposed between said guard carrying element and said tiltable element and arranged to be placed under tension during such additional movement, and a stop element arranged to engage a portion of the tiltable element and tilt the same out of normal position when the press plunger reaches its upper limit of movement.

6. In a device of the character described, the combination with a reciprocatory press plunger, of a tiltable element carried there by, a guard carrying element carried by said reciprocatory element and capable of movement with relation thereto, means for limiting the movement of said guard carrying element, said tilting-element being capable of a limited additional movement in conjunction with the press plunger after the movement of the guard carrying element ceases, spring means disposed between said guard carrying element and said tiltable element and arranged to be placed under tension during such additional movement, a brake mechanism, a controlling mechanism for said brake mechanism, and a member carried by the tiltable element for engaging said controlling mechanism when the tiltable element is tilted from its normal position.

7. In a device of the character described, the combination with a reciprocatory press plunger, of a tiltable element carried thereby, a guard carrying element carried by said reciprocatory element and capable of movement with relation thereto, means for limiting the movement of said guard carrying element, said tilting element being capable of a limited additional movement in conjunction ith the press plunger after the movement of the guard carrying element ceases, spring means disposed between said guard carrying element and said tiltable element and arranged to be placed under tension during such additional movement, and spring means engaging the press plunger and said tiltable element, and normally tending to draw said tiltable element to vertical position.

8. The combination with a press and its driving shaft, of a ratchet carried by said shaft, a pawl lever, spring means normally tending to move said pawl lever into engagement with said ratchet, an oscillating lever normally holding said pawl lever out of action, a cam carried by said oscillating lever, a reciprocatory plunger, a tiltable element carried thereby, a guard carrying ele ment movable in said tiltable element, and a cam engaging member supported by said tiltable element and arranged to engage said cam and shift the oscillating lever to re lease the pawl and permit the latter to move into engagement with said ratchet element when said tiltable element is tilted from its normal position.

9. The combination with a press and its driving shaft, of a ratchet carried by said shaft, a pawl lever, spring means normally tending to move said pawl lever into engagement with said ratchet, an oscillating lever normally iolding said pawl lever out of action, a cam carried by said oscillating lever, a reciprocating plunger, a tiltable element carried thereby, a guard carrying element movable in said tiltable element, a cam engaging member supported by said tiltable element and arranged to engage said cam and shift the oscillating lever to release the pawl and permit the latter to move into engagement with said ratchet when said tiltable element is tilted from its normal position.

10. The combination with a press and its driving shaft, of a ratchet carried by said shaft, a pawl lever, spring means normally tending to move said pawl lever into engagement with said ratchet, an oscillating lever normally holding said pawl lever out of action, a cam carried by said oscillating lever, a reciprocatory plunger, a tiltable element carried thereby, a guard carrying ele ment movable in said tiltable element, a cam engaging member supported by said tiltable element and arranged to engage said cam and shift the oscillating lever to release the pawl and permit the latter to move into engagement with said ratchet when said tiltable element is tilted from its normal po sition, and means for adjusting said cam upon said oscillating lever.

11. The combination with a press and its driving shaft, of a ratchet carried by said shaft, a pawl lever, spring means normally tending to move said pawl lever into en gagement with said ratchet, an oscillating lever normally holding said pawl out of action, a cam carried by said oscillating lever, a reciprocatory plunger, a tiltable element carried thereby, a guard carrying element movable in said tiltable element, a cam engaging member supported by said tiltable element and arranged to engage said cam and shift the oscillating lever to release the pawl and permit the latter to move into engagement with said ratchet element when said tiltable element is tilted from its normal position, and means for adjusting the normal position of said guard carrying element with relation to said tiltable element.

12. The combination with a press and its driving shaft, of a ratchet carired by said shaft, a pawl lever, spring means normally tending to move said pawl lever into engagement with said ratchet, an oscillating lever normally holding said pawl lever out of action, a cam carried by said oscillating lover, a reciprocatory plunger, a tiltable element carried thereby, a guard carrying element movable in said tiltable element, a cam engaging member supported by said tiltable element and arranged to engage said cam and shift the oscillating lever to release the pawl and permit the latter to move into engagement with said ratchet when said tiltable element is tilted from its normal position, and means for limiting the downward movement of said guard carrying element with said tiltable element.

13. The combination with a press and its driving shaft, of a ratchet carried by said shaft, a pawl lever, spring means normally tending to move said pawl lever into engagement with said ratchet, an oscillating lever normally holding said pawl lever out of action, a cam carried by said oscillating lever, a reciprocatory plunger, a tiltable element carried thereby, a guard carrying element movable in said tiltable element, a cam engaging member supported by said tiltable element and arranged to engage said cam and shift the oscillating lever to release the pawl and permit the latter to move into engagement with said ratchet when sald til able element is tilted from its normal position, means for limiting the downward movement ofsaid guard carrying element with said tiltable element, and means for adjusting the degree of downward movement of the guard carrying element.

14:. in a device of the character described, the combination with a press and its reciprocatory plunger, of a tiltable block mounted upon said press plunger and bodily movable therewith, a guard carrying bar mounted for vertical reciprocation in said block, spring means interposed between a portion of said block and a portion of said bar, for resisting the movement of the bar with relation to the block in one direction, a fixed element through which said bar passes, and stop members carried by said bar for engaging with said fixed element to limit the downward movement of the guard carrying bar.

15. in a device of the character described, the combination with a press and its reciprocatory plunger, of a tiltable block mounted upon said press plunger and bodily movable therewith, a guard carrying bar mounted for vertical reciprocation in said block, spring means interposed between a portion of said block and a portion of said bar, for resisting the movement of the bar with relation to the block in one direction, a fixed element through which said bar passes, stop members carried by said bar for engaging with said fixed element to limit the downward movement of the guard carrying bar, and means for adjusting the position of saidstop members with relation to said fixed element.

16. In a device of the character described, the combination with a press and its reciprocatory plunger, of a tiltable block mounted upon said press plunger and bodily movable therewith, a guard carrying bar mounted for vertical reciprocation in said block, spring means interposed between a portion of said block and a portion of said bar, for resisting the movement of the bar with relation to the block in one direction, a fixed element through which said bar passes, stop members carried by said bar for engaging with said fixed element to limit the downward movement of the guard carrying bar, and a stop member carried by said fixed element for engaging a portion of said block to tilt said block out of normal position when the press plunger reaches its upper limit of movement.

17. The combination with a press and its reciprocatory plunger, of a tiltable block pivoted upon said plunger, and bodily movable therewith, a guard carrying bar vertically slidable through said block, spring means resisting upward movement of said bar with relation to said block, a stop member for limiting the downward movement of said bar, a cam engaging element carried by said block, a pivoted latch lever, a cam car ried by said latch lever, and a brake element normally held out of action by said latch lever.

18. The combination with a press and its reciprocatory plunger, of a tiltable block pivoted upon said plunger, and bodily movable therewith, a guard carrying bar vertically slidable through said block,.spring means resisting upward movement of said bar with relation to said block, a stop'member for limiting the downward movement of said bar, a cam. engaging element carried by said block, a pivoted latch lover, a cam carried by said latch lever, a brake element normally held out of action by said latch lever, and means for adjusting said cam upon said last named lever.

19. In a protective device for punch presses, the combination with the press driving shaft, of a toothed collar carried there by, a lever pivoted to the press frame and having an end adapted to engage the teeth of said collar, a spring normally tending to move said end into engagement with said collar, an oscillating lever, one end of which is disposed in position to hold the first named lever out of engaging position, a cam carried by the last named lever, a tiltable element mounted upon the press'plunger, a cam engaging element carried by said tiltable element, and a guard carrying ele ment carried by said tiltable element.

20. In a protective device for punch presses, the combination with the press driving shaft, of a toothed collar carried thereby, a lever pivoted to the press frame and having an end adapted to engage the teeth of said collar, a spring normally tending to move said end into engagement with said collar, an oscillating lever, one end of which 7 is disposed in position to hold the first named lever'out of engaging position, a cam carried by the last named'lever, a tiltable element mounted upon the press plunger, a cam engaging element carried by said tiltable element, a guard carrying element carried by said tiltable element, said guard carrying element being capable of vertical movement with relation to said tiltable element, and means for limiting the downward movement of said guard carrying element, said tiltable element being capable of a limited additional' downward movement after the movement of the guard carrying element ceases. 21. In a protective device for punch presses, the combination with the press driving shaft, of a toothed collar carried thereby, a lever pivoted to the press frame and having an end adapted to engage the teeth of said collar, a springnormally tending to move said end into engagement with said collar, an oscillating lever,one end of which is disposed in position to hold the first named lever out of engaging position, a cam carried by the last named lever, a tiltable element mounted uponthe press plunger, a cam engaging element carried by said tiltable element, a guard carrying element carried by said tiltable element, said guard carry ing element being capable of vertical movement with relation to said tiltable element, means for limiting the downward movement of said'guard carrying element, said tilt- I ableelement being capable of a limited addi- 'tional downward movement after the movement of the guard carrying element ceases, and spring means arranged between said tiltable element and said guard carrying element which means are placed under tension during such additional downward movement of the tiltable element.

22." In a protective device for punch presses, the combination with the press driving shaft, of a toothed collar carried thereby, a lever pivoted to the press frame and having an end adapted to engage the teeth of said collar, a spring normally tending to move said end into engagement with said collar, an oscillating lever, one end of which is disposed in position to hold the first named lever out of engaging position, a cam carried by the last named lever, a tiltable element mounted upon the press plunger, a cam engaging element carried by said tiltable element, a guard carrying element carried by said tiltable element, said guard carrying element being capable of vertical movement with relation to said tiltable element, means for limiting the downward movement of said guard carrying element, said tiltable element being capable of a limited additional downward movement after the moven'ient of the guard carrying element ceases, spring means arranged between said tiltable element and said guard carrying element which means are placed under tension during such additional downward movement of the tiltable element, and a fixed stop member for engaging a portion of said tiltable element and tilting the latter in such manner as to swing the guard carrying element out of position when the press plunger reaches its upper limit of movement.

23. In a device of the character described the combination with the press plunger, of a tiltable element mounted upon said plunger and traveling therewith, a guard element carried by said tiltable element, a brake mechanism, and means controllable by the tilting of said element from normal position for throwing said brake mechanism into action to arrest the movement of the plunger.

24. In a device of the character described. the combination with a press plunger, of a tiltable element mounted thereon and movable bodily therewith, a guard clement h aving yielding engagement with said tiltable element, a brake mechanism, and means controllable by the tilting of said tiltable element from normal position for throwing said brake mechanism into action to arrest the movement of said plunger.

Signed at Hamilton, county of Wentworth, Province of Ontario, Canada, this 81st day of July, A. D. 1913.

' JAMES WRIGHT.

In the presence of ALFRED '1. BRATTON, Gnnrm NIcrroLsoN,

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G.

ISC

DISCLAIMER.

1,135,480.Ja,mes VVTtghE', Hamilton, Ontario, Canada. SAFETY-GUARD FOR POWER- PRESSES. Patent dated April. 13, 1915. Disclaimer filed February 14, 1916, by the patentee. Enters this disclaimer- To claim 23 of the aforesaid Patent 1,135,480, which claim reads as follows:

23. In a device of the character described, the combination with the press plunger, of a tiltable element mounted upon said plunger and traveling therewith, a guard element carried by said tiltable element, a brake mechanism, and means controllable by the tilting of said element from normal position for throwing said brake mechanism into action, to arrest the movement of said plunger.

[Ofiicial Gazette, February 29, 1.916.] 

